title: Effect of chemical cleaning agents on the flexural strength of acrylic and hard denture line resins.
abstract: This study sought to evaluate the disinfectants, Efferdent (EF) and 0.5% sodium hypochlorite (SH), and their effects on the flexural strength and modulus of elasticity of the hard denture liners, Kooliner (K) and New Truliner (NT), and a thermoacrylic resin, QC-20. Ninety specimens were made (50 mm x 10 mm x 3 mm) and divided into 9 groups (n = 10). The 3 control groups were Group 1: QC-20 without disinfection cycles, Group 2: K, and Group 3: NT. The 6 experimental groups were Group 4: QC-20 in EF, Group 5: K in EF, Group 6: NT in EF, Group 7: QC-20 in SH, Group 8: K in SH, and Group 9: NT in SH. Specimens were subjected to 360 cycles of disinfection involving 35-minute cycles of immersion in cleaning solutions. The materials' flexural strength and modulus of elasticity were determined using a universal testing machine at a 5 mm/minute speed of compression. The data were subjected to ANOVA, Tukey, Kruskal-Wallis, and Dunn tests (α = 0.05). Regardless of the disinfection method used, the NT hard denture liner showed the lowest flexural strength values (P < 0.05) and modulus of elasticity (P < 0.0001) compared to K and QC-20. However, flexural strength values increased after applying SH and EF (P < 0.05). QC-20 showed a higher modulus of elasticity (P < 0.033), which increased after EF was applied (P = 0.005). It can be concluded that the disinfection methods changed the mechanical properties of the tested materials.
authors.affiliation: Department of Prosthesis and Periodontology, Dental College of Piracicaba, Sao Paulo, Brazil.
authors.forename: Sabrina Alessandra
authors.initials: SA
authors.lastname: Rodrigues
authors.forename: Juliana Maria Costa
authors.initials: JM
authors.lastname: Nunez Pantoja
authors.forename: Jessica Mie Ferreira Koyama
authors.initials: JM
authors.lastname: Takahashi
authors.forename: Rafael Leonardo Xediek
authors.initials: RL
authors.lastname: Consani
authors.forename: Marcelo Ferraz
authors.initials: MF
authors.lastname: Mesquita
mesh_terms: D003819:Denture Bases; D003822:Denture Liners; D003778:Dentures; D004203:Disinfection; D006244:Hardness; D008422:Materials Testing; D018583:Pliability
keywords: acrylic resin; disinfection; flexural strength; mechanical properties